Batteries removed - solar controller still trying to charge batteries

VFR Bill

Member
Joined
Jul 29, 2023
Messages
18
Hi everyone,

Happy Holidays, hope everyone's doing well. As part of my winterization, I removed the two external lead-acid batteries and put them inside on a trickle charge. The solar collector is uncovered. Could I just cover the solar collector and stop it from trying to charge batteries that aren't there? Is this a harmful setup for the solar controller? Thanks very much,

Bill Palmer
Hedgesville, WV
 
I would have left the batteries in place and allowed the solar to trickle charge them

depending on the controller you may have to cover the panels or disconnect the controller
I assume mostly the controllers that can be used for 12 or 24 v i, they may need the battery to work out what voltage to produce?
 
Why did you remove the batteries? Theft is the only rationale I can think of. Fully charged and completely disconnected lead acid batteries will winter over just fine without any attention whatsoever. November to April. Mine have always come out well over 50% charged sitting in my boats on cradles in the Lake Erie show belt. Camper in a barn at the fairgrounds likewise.
 
It won’t hurt anything. No current is flowing but it shows it available. Much like when your battery is fully charged the panels are still able to generate a charge but don’t since the battery will not draw current.
 
It won’t hurt anything. No current is flowing but it shows it available. Much like when your battery is fully charged the panels are still able to generate a charge but don’t since the battery will not draw current.
^^This^^
As long as the battery cable ends are protected from touching anything or each other, it is perfectly fine. While the panels can/are able to produce power, it cannot go anywhere without a closed circuit. (battery)
 
If your controller output wires are still connected to the RV wiring, they could be powering your parasitic loads.
If they went directly to the battery posts and at least one is not connected to any other wiring, your good.
Having a fuse or switch that can be opened is useful in this situation.
 
I would prefer to just leave the batteries in place and connected and let the solar system do the job as intended. No harm will come from this plus you will have fully charged batteries.

As to the trickle charger, "more stuff means more issues". I see no need for a trickle charger.

Bob
 
Hi everyone,

Happy Holidays, hope everyone's doing well. As part of my winterization, I removed the two external lead-acid batteries and put them inside on a trickle charge. The solar collector is uncovered. Could I just cover the solar collector and stop it from trying to charge batteries that aren't there? Is this a harmful setup for the solar controller? Thanks very much,

Bill Palmer
Hedgesville, WV

Solar controllers are designed to be connected to a battery before the solar panels are connected. I would disconnect the solar controller from the panels before you do anything else. Then maybe, as others have said above, cover the panels for the winter or reconnect the batteries and then connect the panels again. The solar controller is designed to measure the battery type and voltage before the panels are connected so it can provide the correct volts.


"Charge Controllers need a battery connected in order to have a voltage reference and a current sink, two electrical properties essential to their design. Hooking up PV panels without those necessary elements is like driving off the mountain in a truck with no breaks. Putting the right pedal to the metal is all well and good. Putting the left pedal to the metal will have one singing with the angels in no time.

That one is confronted with the drudgery of disconnecting the PV wiring from the charge controller in order to replace the battery is a sure and certain sign the system is missing an extremely important safety element - a PV array disconnect. There should be an appropriately sized circuit breaker on the PV+ lead between the panel array and the charge controller PV+ input."

 
not sure if it is all necessary ... I have accidentally disconnected battery
my controller didn't die

50-50 say it is one way or the other
I say try do as the owners manual for the controller suggests
Just to be on the safer side

I think there was a video on the subject from W Prowse?
 
not sure if it is all necessary ... I have accidentally disconnected battery
my controller didn't die

50-50 say it is one way or the other
I say try do as the owners manual for the controller suggests
Just to be on the safer side

I think there was a video on the subject from W Prowse?
Agreed.
I've disconnected/reconnected my battery cables (with factory solar) more times than I can count on both hands. My controller didn't die either. I even asked the manufacturer this question at last year's Tampa R/V Show and they approved.

But... everyone should do as they see proper.
 
Solar controllers are designed to be connected to a battery before the solar panels are connected. I would disconnect the solar controller from the panels before you do anything else. Then maybe, as others have said above, cover the panels for the winter or reconnect the batteries and then connect the panels again. The solar controller is designed to measure the battery type and voltage before the panels are connected so it can provide the correct volts.



"Charge Controllers need a battery connected in order to have a voltage reference and a current sink, two electrical properties essential to their design. Hooking up PV panels without those necessary elements is like driving off the mountain in a truck with no breaks. Putting the right pedal to the metal is all well and good. Putting the left pedal to the metal will have one singing with the angels in no time.

That one is confronted with the drudgery of disconnecting the PV wiring from the charge controller in order to replace the battery is a sure and certain sign the system is missing an extremely important safety element - a PV array disconnect. There should be an appropriately sized circuit breaker on the PV+ lead between the panel array and the charge controller PV+ input."
If this were really a problem, then the thousands of RVs sitting on dealership lots with no batteries installed until purchase, and with factory installed solar, would be resulting in many damaged SCCs.
 
I’m not sure it is required or are they designed for a certain connection order. I think they just probably suggest a safe way to hook the system up.

Just like a typical battery disconnect. The safest way is to disconnect the negative terminal first but it really doesn’t matter as long as you don’t touch a ground with your wrench if disconnecting the positive terminal first.

But I don’t know as I don’t have any solar for the RV. I do have a small solar panel to trickle charge the battery on my boat. I know when I disconnect it from the battery the blue light keeps blinking while in the sun. There is no on/off switch.
 
The issue is really SCC manufacturer and model specific. Some are 12 or 24 voltage and having a battery connected prior to connecting PV panels starts things " on the right foot".

One can cover panels with a rubber mat or similar that's heavy enough to not be blown away or install a fairly inexpensive double pole switch on wires from panels to SCC.a
 
I put in a Solar Controller shut off switch between my panels and controller. Posts on putting one in but isn't this one of those, the manufacturers do it all the time? And campers are sold every day without harm to their controllers. If it was a real problem shut off switches would be installed or panels covered.

Once shoved out their doors they sit outside in the sun without batteries.

Edit: Yes I would protect the battery ends if I was removing the cables for any length of time and just made sure they were not contacting anything when I did disconnect them for the short times I have.
 
Last edited:
I would have left the batteries in place and allowed the solar to trickle charge them

depending on the controller you may have to cover the panels or disconnect the controller
I assume mostly the controllers that can be used for 12 or 24 v i, they may need the battery to work out what

I would have left the batteries in place and allowed the solar to trickle charge them

depending on the controller you may have to cover the panels or disconnect the controller
I assume mostly the controllers that can be used for 12 or 24 v i, they may need the battery to work out what voltage to produce?
HI Aussieguy, thank you for the suggestion, it sure is easier to leave the batteries in place. Being a newbie camper, I was advised to disconnect the batteries and bring them inside for the winter, which I did last year. Thanks again! -Bill P
 
Why did you remove the batteries? Theft is the only rationale I can think of. Fully charged and completely disconnected lead acid batteries will winter over just fine without any attention whatsoever. November to April. Mine have always come out well over 50% charged sitting in my boats on cradles in the Lake Erie show belt. Camper in a barn at the fairgrounds likewise.
Hi Chuck_S, thank you fore the info. I'm a newbie camper, and was advised to bring the batters indoors over the winter. Thankfully, not concerned about theft the camper is parked for the winter. I did that last winter, putting the batts on a trickle charge. But your experience encourages me to put the batteries back in place. Thanks again. -Bill P
 
Hope everyone had an excellent holiday, and here comes 2025! The consensus I got was that I can leave the batteries connected to the system and let the solar controller trickle-charge them. When I removed the batteries, there's an external rotary disconnect switch directly behind the battery cases, which I turned to the DISC position before removing the batteries. I taped the cable ends with electrical tape. I believe I have a 12-volt system on the DC side. So, thanks very much, I appreciate the collective wisdom and experience you all bring to this forum. Happy New Year! -Bill P
 
Please carefully research "what someone told you" as being accurate or necessary. A LOT of information circulating is not complete nor correct. Fully charged and completely disconnected lead acid batteries will winter over just fine without any attention whatsoever. November to April.

Disconnect the NEG cable at the battery and be done with it until next Spring.

Bob
 
Hi Bob, thanks for the advice. Being a newbie camper, I leaned on the RV dealer for advice, and that's what I was going with. Two concerns I've had that have been unraveled on this forums are: (1) leaving the trailer out in the weather, and (2) bringing the batteries indoors in winter. Per others on this thread, I think it's a good idea to leave the batteries connected to the solar charging system, and let the solar controller trickle-charge them over the winter.
 
Bill, There are many knowledgeable folks on this forum. I’ve learned much from many of them. If in the future you have any questions, just ask. No question too small. We’ve all been where you are (newbie) and learned much from experience and this forum… Don
 

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top Bottom